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      1 // Copyright 2013 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef MEDIA_CAST_RTCP_RTCP_H_
      6 #define MEDIA_CAST_RTCP_RTCP_H_
      7 
      8 #include <map>
      9 #include <queue>
     10 #include <string>
     11 
     12 #include "base/basictypes.h"
     13 #include "base/memory/scoped_ptr.h"
     14 #include "base/time/tick_clock.h"
     15 #include "base/time/time.h"
     16 #include "media/cast/base/clock_drift_smoother.h"
     17 #include "media/cast/cast_config.h"
     18 #include "media/cast/cast_defines.h"
     19 #include "media/cast/cast_environment.h"
     20 #include "media/cast/rtcp/receiver_rtcp_event_subscriber.h"
     21 #include "media/cast/rtcp/rtcp_defines.h"
     22 #include "media/cast/transport/cast_transport_defines.h"
     23 #include "media/cast/transport/cast_transport_sender.h"
     24 #include "media/cast/transport/pacing/paced_sender.h"
     25 
     26 namespace media {
     27 namespace cast {
     28 
     29 class LocalRtcpReceiverFeedback;
     30 class LocalRtcpRttFeedback;
     31 class PacedPacketSender;
     32 class RtcpReceiver;
     33 class RtcpSender;
     34 
     35 typedef std::pair<uint32, base::TimeTicks> RtcpSendTimePair;
     36 typedef std::map<uint32, base::TimeTicks> RtcpSendTimeMap;
     37 typedef std::queue<RtcpSendTimePair> RtcpSendTimeQueue;
     38 
     39 class RtcpSenderFeedback {
     40  public:
     41   virtual void OnReceivedCastFeedback(const RtcpCastMessage& cast_feedback) = 0;
     42 
     43   virtual ~RtcpSenderFeedback() {}
     44 };
     45 
     46 class RtpReceiverStatistics {
     47  public:
     48   virtual void GetStatistics(uint8* fraction_lost,
     49                              uint32* cumulative_lost,  // 24 bits valid.
     50                              uint32* extended_high_sequence_number,
     51                              uint32* jitter) = 0;
     52 
     53   virtual ~RtpReceiverStatistics() {}
     54 };
     55 
     56 class Rtcp {
     57  public:
     58   // Rtcp accepts two transports, one to be used by Cast senders
     59   // (CastTransportSender) only, and the other (PacedPacketSender) should only
     60   // be used by the Cast receivers and test applications.
     61   Rtcp(scoped_refptr<CastEnvironment> cast_environment,
     62        RtcpSenderFeedback* sender_feedback,
     63        transport::CastTransportSender* const transport_sender,  // Send-side.
     64        transport::PacedPacketSender* paced_packet_sender,       // Receive side.
     65        RtpReceiverStatistics* rtp_receiver_statistics,
     66        RtcpMode rtcp_mode,
     67        const base::TimeDelta& rtcp_interval,
     68        uint32 local_ssrc,
     69        uint32 remote_ssrc,
     70        const std::string& c_name,
     71        EventMediaType event_media_type);
     72 
     73   virtual ~Rtcp();
     74 
     75   static bool IsRtcpPacket(const uint8* rtcp_buffer, size_t length);
     76 
     77   static uint32 GetSsrcOfSender(const uint8* rtcp_buffer, size_t length);
     78 
     79   base::TimeTicks TimeToSendNextRtcpReport();
     80 
     81   // Send a RTCP sender report.
     82   // |current_time| is the current time reported by a tick clock.
     83   // |current_time_as_rtp_timestamp| is the corresponding RTP timestamp.
     84   void SendRtcpFromRtpSender(base::TimeTicks current_time,
     85                              uint32 current_time_as_rtp_timestamp);
     86 
     87   // |cast_message| and |rtcp_events| is optional; if |cast_message| is
     88   // provided the RTCP receiver report will append a Cast message containing
     89   // Acks and Nacks; if |rtcp_events| is provided the RTCP receiver report
     90   // will append the log messages.
     91   void SendRtcpFromRtpReceiver(
     92       const RtcpCastMessage* cast_message,
     93       const ReceiverRtcpEventSubscriber::RtcpEventMultiMap* rtcp_events);
     94 
     95   void IncomingRtcpPacket(const uint8* rtcp_buffer, size_t length);
     96 
     97   // TODO(miu): Clean up this method and downstream code: Only VideoSender uses
     98   // this (for congestion control), and only the |rtt| and |avg_rtt| values, and
     99   // it's not clear that any of the downstream code is doing the right thing
    100   // with this data.
    101   bool Rtt(base::TimeDelta* rtt,
    102            base::TimeDelta* avg_rtt,
    103            base::TimeDelta* min_rtt,
    104            base::TimeDelta* max_rtt) const;
    105 
    106   bool is_rtt_available() const { return number_of_rtt_in_avg_ > 0; }
    107 
    108   // If available, returns true and sets the output arguments to the latest
    109   // lip-sync timestamps gleaned from the sender reports.  While the sender
    110   // provides reference NTP times relative to its own wall clock, the
    111   // |reference_time| returned here has been translated to the local
    112   // CastEnvironment clock.
    113   bool GetLatestLipSyncTimes(uint32* rtp_timestamp,
    114                              base::TimeTicks* reference_time) const;
    115 
    116   // Set the history size to record Cast receiver events. The event history is
    117   // used to remove duplicates. The history will store at most |size| events.
    118   void SetCastReceiverEventHistorySize(size_t size);
    119 
    120   // Update the target delay. Will be added to every report sent back to the
    121   // sender.
    122   // TODO(miu): Remove this deprecated functionality. The sender ignores this.
    123   void SetTargetDelay(base::TimeDelta target_delay);
    124 
    125   void OnReceivedReceiverLog(const RtcpReceiverLogMessage& receiver_log);
    126 
    127  protected:
    128   void OnReceivedNtp(uint32 ntp_seconds, uint32 ntp_fraction);
    129   void OnReceivedLipSyncInfo(uint32 rtp_timestamp,
    130                              uint32 ntp_seconds,
    131                              uint32 ntp_fraction);
    132 
    133  private:
    134   friend class LocalRtcpRttFeedback;
    135   friend class LocalRtcpReceiverFeedback;
    136 
    137   void OnReceivedDelaySinceLastReport(uint32 receivers_ssrc,
    138                                       uint32 last_report,
    139                                       uint32 delay_since_last_report);
    140 
    141   void OnReceivedSendReportRequest();
    142 
    143   void UpdateRtt(const base::TimeDelta& sender_delay,
    144                  const base::TimeDelta& receiver_delay);
    145 
    146   void UpdateNextTimeToSendRtcp();
    147 
    148   void SaveLastSentNtpTime(const base::TimeTicks& now,
    149                            uint32 last_ntp_seconds,
    150                            uint32 last_ntp_fraction);
    151 
    152   scoped_refptr<CastEnvironment> cast_environment_;
    153   transport::CastTransportSender* const transport_sender_;
    154   const base::TimeDelta rtcp_interval_;
    155   const RtcpMode rtcp_mode_;
    156   const uint32 local_ssrc_;
    157   const uint32 remote_ssrc_;
    158   const std::string c_name_;
    159   const EventMediaType event_media_type_;
    160 
    161   // Not owned by this class.
    162   RtpReceiverStatistics* const rtp_receiver_statistics_;
    163 
    164   scoped_ptr<LocalRtcpRttFeedback> rtt_feedback_;
    165   scoped_ptr<LocalRtcpReceiverFeedback> receiver_feedback_;
    166   scoped_ptr<RtcpSender> rtcp_sender_;
    167   scoped_ptr<RtcpReceiver> rtcp_receiver_;
    168 
    169   base::TimeTicks next_time_to_send_rtcp_;
    170   RtcpSendTimeMap last_reports_sent_map_;
    171   RtcpSendTimeQueue last_reports_sent_queue_;
    172 
    173   // The truncated (i.e., 64-->32-bit) NTP timestamp provided in the last report
    174   // from the remote peer, along with the local time at which the report was
    175   // received.  These values are used for ping-pong'ing NTP timestamps between
    176   // the peers so that they can estimate the network's round-trip time.
    177   uint32 last_report_truncated_ntp_;
    178   base::TimeTicks time_last_report_received_;
    179 
    180   // Maintains a smoothed offset between the local clock and the remote clock.
    181   // Calling this member's Current() method is only valid if
    182   // |time_last_report_received_| is not "null."
    183   ClockDriftSmoother local_clock_ahead_by_;
    184 
    185   // Latest "lip sync" info from the sender.  The sender provides the RTP
    186   // timestamp of some frame of its choosing and also a corresponding reference
    187   // NTP timestamp sampled from a clock common to all media streams.  It is
    188   // expected that the sender will update this data regularly and in a timely
    189   // manner (e.g., about once per second).
    190   uint32 lip_sync_rtp_timestamp_;
    191   uint64 lip_sync_ntp_timestamp_;
    192 
    193   base::TimeDelta rtt_;
    194   base::TimeDelta min_rtt_;
    195   base::TimeDelta max_rtt_;
    196   int number_of_rtt_in_avg_;
    197   double avg_rtt_ms_;
    198   uint16 target_delay_ms_;
    199 
    200   DISALLOW_COPY_AND_ASSIGN(Rtcp);
    201 };
    202 
    203 }  // namespace cast
    204 }  // namespace media
    205 
    206 #endif  // MEDIA_CAST_RTCP_RTCP_H_
    207